1. Field of the Invention
The present invention relates to a copying machine, and more particularly to an electronic copying machine being capable of adjusting copying magnifications in a lateral direction and a longitudinal direction independently based on the adjusting values stored in the copying machine and the copying machine is provided with discriminating means for discriminating the kind of papers mounted in a paper feeding unit, whereby the copying magnifications set at the time of making copy are adjusted based on adjusting values which are read out corresponding to the kind of the paper discriminated by the discriminating means.
2. Description of the Related Art
It is noted that the words lateral direction and longitudinal direction in the specification and claims mean the directions of both sides of a right angle of the copying paper and, for example, the longitudinal direction means the direction of the long side of square shaped papers and the lateral direction means the direction of the short side thereof.
Copy magnification in copying machines have specific errors in a lateral direction and a longitudinal direction based on dispersion at the time of production process of the copying machines. The copying papers expand or shrink due to paper quality, the moisture content and condition of the circumstance such as temperature and humidity and the value of the expansion and shrinkage of the paper differs depending on the various conditions mentioned above. Moreover, in the copying process, there is a transfer process in which toner is pressed to a copying paper with heat, wherein the paper size is also changed.
Therefore, it is not easy to really make up a copy of a picture with a correct magnification. Especially, with respect to drawings, size of an article may be measured from a copied drawing. Therefore, in a copying machine for copying drawings, it is requested to make copy with a correct magnification. For this requirement, there is proposed a copying machine in which the copy magnification in the longitudinal and lateral directions are independently adjustable in the Japanese patent publication (unexamined) No. 61-77833.
There are following three main causes of adjusting the copy magnification:
(1) the error being proper in the copying machine; PA1 (2) change of the copying magnification due to change of the original; PA1 (3) natural expansion or shrinkage of the copying paper or correction against the size change of the copying paper in the copying process. PA1 image forming means for forming an image of an original to be copied on a copying paper; PA1 magnifying means for setting copy magnifications in a longitudinal direction and a lateral direction independently; PA1 first selecting means for selecting any one of the copy magnifications preliminarily stored; PA1 first magnification control means for controlling said magnifying means so that the copy of the original has such magnifications in the longitudinal and lateral directions as selected by said first selecting means; PA1 a plurality of memory means each comprising memory areas for storing a pair of adjusting values for adjusting the copy magnifications, the pair of adjusting values being a first adjusting value in the longitudinal direction and a second adjusting value in the lateral direction; PA1 second selecting means for selecting one of said memory means; PA1 second magnification control means for controlling said magnifying means based on the pair of adjusting values stored in said selected memory means and the copy magnifications selected by said first selecting means.
In the above, change of the copying paper is the most important cause.
Conventionally, however, the copy magnification is manually adjusted considering the above three major causes as one unseparated cause. Therefore, according to the conventional copying machine, such adjustment must be made every copy. In addition since the copy magnification is adjusted by comparing the copied picture with the original picture, it is necessary to repeat the adjustment of the copy magnification several times until the copy with the desired copy magnification can be obtained. Therefore, not only copy paper but also time are wasted and it is required to improve the operability of the copying machine.
Besides, as to the copying papers used in the copying machine, the rate of the expansion and shrinkage of the copy paper itself and the rate of the expansion and shrinkage of the copy paper in the copy process in the longitudinal direction and the lateral direction are substantially constant if the kind of copy paper is unchanged, whereby in case copy papers of the same kind are used, it is not necessary to repeat the adjustment of the copy magnification once the copy magnification is adjusted.